title: Transcriptome profiling in crustaceans as a tool for ecotoxicogenomics: Daphnia magna DNA microarray.
abstract: Chemicals released into the environment have the potential to affect various species and it is important to evaluate such chemical effect on ecosystems, including aquatic organisms. Among aquatic organisms, Daphnia magna has been used extensively for acute toxicity or reproductive toxicity tests. Although these types of tests can provide information on hazardous concentrations of chemicals, they provide no information on their mode of action. Recent advances in toxicogenomics, the integration of genomics with toxicology, have the potential to afford a better understanding of the responses of aquatic organisms to pollutants. In a previous study, we developed an oligonucleotide-based DNA microarray with high reproducibility using a Daphnia expressed sequence tag (EST) database. In this study, we increased the number of genes on the array and used it for a careful ecotoxicogenomic assessment of Daphnia magna. The DNA microarray was used to evaluate gene expression profiles of neonate daphnids exposed to beta-naphthoflavone (bNF). Exposure to this chemical resulted in a characteristic gene expression pattern. As the number of the genes on an array was increased, the number of genes that were found to respond to the chemicals was also increased, which made the classification of the toxic chemicals easier and more accurate. This newly developed DNA microarray can be useful for a obtaining a better mechanistic understanding of chemical toxicity effects on a common freshwater organism.
authors.affiliation: Okazaki Institute of Integrative Bioscience, National Institutes of Natural Sciences, Myodaiji, Okazaki, Japan. watanabe@nibb.ac.jp
authors.forename: Hajime
authors.initials: H
authors.lastname: Watanabe
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Kato
authors.forename: Shigeto
authors.initials: S
authors.lastname: Oda
authors.forename: Ryoko
authors.initials: R
authors.lastname: Abe
authors.forename: Norihisa
authors.initials: N
authors.lastname: Tatarazako
authors.forename: Taisen
authors.initials: T
authors.lastname: Iguchi
mesh_terms: D000818:Animals; D001483:Base Sequence; D016000:Cluster Analysis; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D015342:DNA Probes; D003621:Daphnia / Q000187:drug effects / Q000235:genetics*; D054750:Ecotoxicology; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000633:toxicity; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D023281:Genomics; D020411:Oligonucleotide Array Sequence Analysis; D015203:Reproducibility of Results; D019324:beta-Naphthoflavone / Q000633:toxicity
chemical_list: D015342:DNA Probes; D004785:Environmental Pollutants; D019324:beta-Naphthoflavone; D003577:Cytochrome P-450 Enzyme System